1. Energy Flow in Ecosystems

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1 Ecosystems & Biomes 1. Energy Flow in Ecosystems What are energy roles in ecosystems? What are energy roles in ecosystems? Producers An organism that can make its own food = AUTOTROPHS! Source of all the food in an ecosystem Producers make their own food via photosynthesis An organism s energy role is determined by how it gets its food and how it interacts with other organisms There are three energy roles in an ecosystem: Producers Consumers Decomposers

2 What are energy roles in ecosystems? What are energy roles in ecosystems? Consumers An organism that gets energy by feeding on other organisms Consumers are classified by what they eat: Decomposers An organism that breaks down waste and dead organisms to return the materials to the environment Nature s recyclers! Carnivores - eat only animals Herbivores - eat only plants Omnivores - eat both plants and animals Scavengers - carnivore that eats dead animals How does energy move through an ecosystem? How does energy move through an ecosystem? Energy enters ecosystems from the sun Energy moves through an ecosystem when one organism eats another Food chains - a series of events where one organism eats another Food webs - many overlapping food chains in an ecosystem Energy pyramids - shows the amount of energy that moves from one level to another in a food web

3 How do human activities affect ecosystems How do human activities affect ecosystems Human activities affect the balance in an ecosystem and can change the ecosystem: Agriculture Overuse of resources Agriculture Technology that helps increase food production also hurts the environment Clearing forest for farmland Insecticides, herbicides, and fertilizers to increase/help crop production How do human activities affect ecosystems Overuse of resources If humans use too many resources in an ecosystem, the plants and animals don t have enough for them Catching too many fish Too many animals in a grassland area Desertification - when a once fertile area becomes desert like 2. Cycles of Matter

4 What Processes are involved in the water cycle? What Processes are involved in the water cycle? The water cycle is the continuous process where water moves from Earth s surface to the atmosphere and back The water cycle is made up of three processes: Evaporation The process where molecules of water absorb energy and turn into a gas Evaporation Condensation precipitation The energy comes from the sun! Liquid water evaporates from oceans, lakes, and other water sources to form water vapor in the atmosphere What processes are involved in the Water Cycle? Condensation As water vapor from evaporation gets higher in the atmosphere, it cools down and eventually turns back into drops of water This is called condensation! Water droplets collect around dust particles to form clouds

5 What processes are involved in the Water Cycle? Precipitation As more water vapor condenses, the drops of water in the clouds get larger until they fall to the earth as rain, snow, sleet, or hail The precipitation that falls will go back into the lakes and oceans, or may be soaked up by soil and become groundwater How are the carbon cycle and oxygen cycle related? The cycling of carbon dioxide and oxygen are linked together with two cycles: Carbon cycle Oxygen cycle

6 How are the carbon cycle and oxygen cycle related? Carbon cycle Producers take in carbon dioxide from the air during photosynthesis and use carbon to make food As consumers eat producers, they take in carbon and break it down by cellular respiration Consumers release carbon dioxide back into the environment How are the carbon cycle and oxygen cycle related? How are the carbon cycle and oxygen cycle related? Oxygen cycle Producers release oxygen after photosynthesis occurs Consumers take in oxygen from the air Human impact When we burn oil, carbon dioxide is released and levels in the environment go up Clearing forests increases levels of carbon dioxide

7 How does nitrogen cycle through ecosystems? How does nitrogen cycle through ecosystems? In the nitrogen cycle, nitrogen moves from the air to the soil, to living things, and back to the air or soil The air around you is about 78% nitrogen gas! Most organisms cannot use nitrogen gas though Nitrogen fixation Most organisms can only use nitrogen that has been combined with other elements How does nitrogen cycle through ecosystems? Once nitrogen is fixed, producers use it to build proteins Nitrogen cycles from the soil to the producers and then to consumers once they are eaten sometimes, bacteria break down some of the nitrogen until it goes back into the air Changing free nitrogen into usable forms of nitrogen is called nitrogen fixation Most nitrogen fixation is done by bacteria that live in the roots of plants like beans, peanuts, peas, and clover

8 3. biomes The climate - the average annual temperature and amount of precipitation - determines the biome of an area Climate limits the types of plants that can grow there, and the types of plants determines the species of animals that can live there A biome is a group of ecosystems with similar climates and organisms There are six major biomes: Desert Rainforest Grassland Deciduous forest Boreal forest tundra Desert - An area that receives less than 25 centimeters of rain a year Deserts go through big changes in temperature in a day! During the day it can be scorching hot, but at night it can drop to below freezing! Organisms in the desert must be adapted to little to no rain and extreme temperatures Cactus plants Gila monsters Fennec

9 Rainforest - an area where large amounts of rain fall in a year After it rains, the sun appears, but very little of it reaches the ground! There are two types of rainforest biomes: Temperate Tropical Temperate rainforest Northwest of the united states Receives more than 300 centimeters of rain a year Huge trees like redwoods, cedars, and firs

10 Tropical rainforest Warm, humid climate with a lot of rain. Perfect for a great variety of plants! Plants: venus fly traps, orchids, rubber trees Animals: Monkey, jaguar, toucan, frogs There are four layers to the trees of a rainforest Emergent layer - the tallest layer, gets the most sunlight Canopy - leafy layer under the emergent Understory - short trees and vines, shaded Forest floor - ground under the trees

11 Grassland - grassy plains, called prairies Comfortable temperatures with 25 to 75 centimeters of rain a year A savanna is a grassland closer to the equator Grasslands are home to large animals such as: Elephants Bison Giraffes Rhinos zebras Deciduous forest - trees shed their leaves and grow new ones each year Around 50 centimeters of rain a year Temperatures vary greatly during the year Trees include oaks and maples Animals include squirrels, chipmunks, and skunks

12 Boreal forest - dense forests found in the northern hemisphere (also known as taiga) Coniferous trees like firs and hemlocks Animals include red squirrels, finches, moose, beavers, and owls Tundra - an extremely cold and dry biome Soil is frozen most of the year, this is called permafrost Plants include moss, grass, and dwarf trees Animals include foxes, caribou, and wolves

13 What are the two major aquatic ecosystems? 4. Aquatic Ecosystems What are the two major aquatic ecosystems? Freshwater Streams and rivers Trout, frogs, snails Ponds and lakes Algae, dragonflies, many types of fish Three quarters of earth s surface is covered in water There are two types of aquatic ecosystems: Freshwater Saltwater (marine) What are the two major aquatic ecosystems? Marine (saltwater) An estuary is where the freshwater meets the saltwater Crabs, algae, fish There are four zones of a marine ecosystem Intertidal zone - on the shore between high tide and low tide barnacles, sea stars, clams, crabs Neritic zone - shallow water below low tide coral reef, schools of fish, algae Surface zone of open ocean meters deep tuna, swordfish, few whales Deep zone of open ocean - from surface zone to floor giant squid, anglerfish

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